Laminate and pneumatic tires made by using the same

ABSTRACT

A laminate of an air permeation preventive layer an adhesive layer provided with an air permeation preventive layer comprising a thermoplastic elastomer composition containing a thermoplastic resin as a continuous phase and a rubber composition dispersed therein as a dispersed phase and arranged on one surface of the air permeation preventive layer, an adhesive composition layer having a thickness of 100 μm or less, a self tack of less than 5N and a tack to an unvulcanized diene-based rubber or 5N or more, containing 100 parts by weight of a thermoplastic elastomer containing 50 parts by weight or more of an epoxy-modified styrene-butadiene-based block copolymer so that a total of 30 to 200 parts by weight of a terpene resin and an aromatically modified terpene resin having a weight average molecular weight Mw of 1000 or less and a softening point of 60 to 120° C., 0.1 to 3 parts by weight of an internal mold release agent and 0.1 to 2 parts by weight of an organic peroxide.

This application is a National Stage of PCT/JP2004/013400 filed Sep. 8,2004 which in turn claims priority from Japanese Application2003-336057, filed Sep. 26, 2003.

TECHNICAL FIELD

The present invention relates to a laminate of an air permeationpreventive layer/an adhesive (or tackifier, same below) layer and apneumatic tire using the same. More specifically, it relates to alaminate of an air permeation preventive layer/an adhesive layer havinga superior bondability to vulcanized rubber, etc., a superiorworkability and suitable for decreasing the weight of a pneumatic tireand to a pneumatic tire using the same.

BACKGROUND ART

The technology of using a thermoplastic elastomer for the air permeationpreventive layer of a pneumatic tire is known in the art (e.g., seeJapanese Patent No. 2999188). For example, when extruding thethermoplastic elastomer, together with an adhesive layer in two layersin cylindrical shapes, if the adhesive layer arranged at the outside istoo tacky, it will stick to the take-up (or wind-up) rolls at the timeof shaping and seriously degrade the workability. Further, this requiresthe insertion of release paper, Mylar®, etc. between the tubularmaterials at the time of take-up—which is a problem in terms of cost andtransport weight. Further, if the adhesive layer is insufficientlytacky, at the time of tire production, there is the problem that the airpermeation preventive layer will end up peeling off from the tirecarcass thereby making formation impossible. Further, if the amount ofthe cross-linking agent in the adhesive composition is too large, thereis the problem of occurrence of scorching in the process of co-extrusionwith the thermoplastic elastomer composition at a high temperature. Notethat Japanese Patent Publication (A) No. 11-240108 proposes a laminateof a thermoplastic resin/a rubber, but the present invention is directedto the different technology in the object and constitution thereof.

DISCLOSURE OF THE INVENTION

Accordingly, the objects of the present invention are to solve theproblems of the above-mentioned prior laminate of air permeationpreventive layer/adhesive layer laminates and to provide a laminate ofan air permeation preventive layer/an adhesive layer capable ofimproving the workability in the production of a pneumatic tire and, forexample, having a superior bondability with a tire carcass andcontributing to the reduction of tire weight.

In accordance with the present invention, there are provided a laminateof an air permeation preventive layer/an adhesive layer provided with(I) an air permeation preventive layer comprising a thermoplasticelastomer composition containing a thermoplastic resin, as a continuousphase, and a rubber composition dispersed therein, as a dispersed phase,and, arranged on one surface of the air permeation preventive layer,(II) an adhesive composition layer having a thickness of 100 μm or lessformed from an adhesive composition having a self tack of less than 5N,and a tack to an unvulcanized diene-based rubber of 5N or morecontaining (i) a total of 100 parts by weight of a thermoplasticelastomer containing 50 parts by weight or more of an epoxy-modifiedstyrene-butadiene-based block copolymer so that an oxirane oxygencontent becomes 1 to 3% by weight, (ii) a total of 30 to 200 parts byweight of a terpene resin (A) and an aromatically modified terpene resin(B) in a ratio of (A):(B)=100:0 to 50:50 (weight ratio) having a weightaverage molecular weight Mw of 1000 or less and a softening point of 60to 120° C., (iii) 0.1 to 3 parts by weight of an internal mold releaseagent and (iv) 0.1 to 2 parts by weight of an organic peroxide. having aone-minute half-life temperature of 160° C. or more, and a pneumatictire using the same.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an inflation molding machine used for atest for evaluation of an adhesive composition in the Examples andComparative examples in this description.

BEST MODE FOR CARRYING OUT THE INVENTION

According to the present invention, it is possible to obtain a laminateof an adhesive composition, which keeps the polymer's self tack (tack ofadhesives with each other) and tack with metal or a vulcanized rubberlow to improve the workability, which exhibits sufficient tack withunvulcanized rubber at the time of tire formation and which is free fromscorching, even when co-extruded at 200° C. or more temperature with athermoplastic elastomer, and a thermoplastic elastomer air permeationpreventive layer. By using this laminate, it is possible to obtainsuperior bondability and possible to obtain a light weight pneumatictire, without affecting the other properties.

The singular forms (e.g., “a”, “an”, and “the”) used in the presentdescription and the attached claims should be understood as includingthe plural form except when otherwise clear from the context.

According to the present invention, an air permeation preventive layercomposed of a thermoplastic elastomer composition having a thermoplasticresin, as a continuous phase, and a rubber composition, as a dispersedphase, is provided at one surface with an adhesive composition layerhaving a self tack of less than 5N, preferably 1 to 4N, a tack to anunvulcanized diene-based rubber of 5N or more, preferably 7 to 20N, anda thickness of 100 μm or less, preferably 5 to 70 μm, to form an airpermeation preventive layer/an adhesive layer laminate.

An air permeation preventive layer used in the present invention andcomposed of a thermoplastic elastomer composition having a thermoplasticresin, as a continuous phase, and a rubber composition, as a dispersedphase, is known. For example, it is possible to use those described inJapanese Unexamined Patent Publication (A) No. 2002-80644, etc.

The adhesive composition usable in the present invention comprises (i) atotal of 100 parts by weight of a thermoplastic elastomer containing atleast 50 parts by weight or more, preferably 60 to 100 parts by weight,of an epoxy-modified (or epoxylated) styrene-butadiene-based blockcopolymer so that an oxirane oxygen content becomes 1 to 3% by weight,preferably 1.2 to 2.8% by weight, (ii) a total of 30 to 200 parts byweight, preferably 40 to 120 parts by weight, of a terpene resin (A)having a weight average molecular weight Mw of 1000 or less, preferably500 to 900 and a softening point of 60 to 120° C., preferably 80 to 110°C., and an aromatically modified terpene resin (B) having a weightaverage molecular weight Mw of 1000 or less, preferably 500 to 900 and asoftening point of 60 to 120° C., preferably 80 to 110° C., in a ratioof (A):(B)=100:0 to 50:50, preferably 100:0 to 70:30 (weight ratio),(iii) 0.1 to 3 parts by weight, preferably 0.2 to 2 parts by weight, ofan internal mold release agent and (iv) 0.1 to 2 parts by weight,preferably 0.3 to 1 part by weight, of an organic peroxide having aone-minute half-life temperature of 160° C. or more, preferably 165 to190° C.

The thermoplastic elastomer usable in the adhesive composition of thepresent invention, as explained above, must contain an epoxy-modifiedstyrene-butadiene-based block copolymer (ESBS) having the specificoxirane oxygen concentration. This epoxy-modification, may be carriedout by epoxylating, for example, a styrene-butadiene-based blockcopolymer (SBS) using peracids or hydroperoxides. As peracids, performicacid, peracetic acid, perbenzoic acid, trifluoroperacetic acid, etc. maybe mentioned. Further, as hydroperoxides, hydrogen peroxide, t-butylhydroperoxide, cumen peroxide, etc. may be mentioned. If the oxiraneoxygen content of the epoxylated SBS copolymer (ESBS) this obtained istoo low, the bondability with the air permeation preventive layer isliable to deteriorate, and therefore, this is not preferred, whileconversely if it is too high, the bondability with the tire rubber isliable to deteriorate, and therefore, this is not preferred. Further, ifthe content of the ESBS copolymer in the thermoplastic elastomer is toosmall, the bondability with the air permeation preventive layer isliable to deteriorate, and therefore, this is not preferred.

As the matrix polymer of the adhesive composition according to thepresent invention constituted by the thermoplastic elastomer, inaddition to the epoxylated SBS copolymer, various SBS copolymers,various styrene-isoprene block (SIS) copolymers and their partialhydrogenates etc. may be used.

The adhesive composition according to the present invention may containa specific terpene resin (A) or a mixture of a terpene resin (A) and anaromatically modified terpene resin (B).

Here, “terpene” is the general term for the series of compounds havingisoprene units. A “terpene resin” is a homopolymerized or copolymerizedproduct mainly composed of oil obtained from pine tree resin or citrusfruit peel (e.g., α-pinene, β-pinene, dipentene (limonene), etc.). Thesolubility with a polymer and the softening point may change dependingon the ratios and molecular weights (i.e., polymerization degrees) andmolecular weight distributions of these monomers. The terpene resin (A)usable in the present invention is preferably, from the viewpoint ofimparting bondability, a copolymer of β-pinene and dipentene or ahomopolymer of dipentene. A homopolymer of dipentene is more preferable.

The aromatically modified terpene resin (B) can be produced by causingthe terpene resin (A) to co-condense with a phenol, alkylphenol, etc. Acommercially available product may also be used. The amount of thearomatic modification of the aromatically modified terpene resin (B) isnot particularly limited, but preferably is about 1 to 20% by weightbased upon the weight of the terpene resin.

The ratio of the terpene-based resin (A)/the aromatically modifiedterpene resin (B) in the present invention may be changed according tothe working environmental conditions (e.g., temperature, humidity, etc.)and the degree of tack of the tire members. If the ratio of the terpeneresin is greater, the self tack and the tack to metal or vulcanizedrubber is decreased and the workability is improved, while conversely ifthe ratio of the aromatically modified terpene resin is greater, thetack with the unvulcanized tire member is improved. From this viewpoint,the present inventors found that, if (A):(B) is made 100:0 to 50:50(weight ratio), preferably 100:0 to 70:30, a good balance thereof can beobtained. Further, if the thickness of the adhesive layer exceeds 100μm, the weight is increased and the durability tends to deteriorate, andtherefore, this is not preferred.

The adhesive composition according to the present invention may contain,therein for further adjusting the tack, an internal mold release agentin an amount of 0.1 to 3 parts by weight, preferably 0.1 to 1 part byweight, based upon the total 100 parts by weight of the thermoplasticelastomer. As the internal mold release agent, for example, thegenerally used stearic acid or oleic acid and their metal salts etc. maybe used. By compounding an internal mold release agent in this way, itis possible, in particular, to lower the self tack. By suitablyadjusting the compounded amount when adjusting the tack so as tocorrespond to the changes in an air temperature etc., it is possible tomaintain the optimal state of tack.

In the present invention, as the cross-linking agent, an organicperoxide having a one-minute half-life temperature of 160° C. or more,preferably 165 to 190° C., is used for the crosslinking in an amount of0.1 to 2 parts by weight, preferably 0.3 to 1 part by weight. As such anorganic peroxide, specifically, for example, dicumyl peroxide,di-t-butyl peroxide, t-butylcumyl peroxide, benzoyl peroxide,2,5-dimethyl-2,5-di (t-butylperoxy)hexine-3, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxyisopropyl) benzene,4,4-di-t-butylperoxy-valerenate-n-butyl ester, etc. may be used.

According to the present invention, the adhesive composition can beplaced between a thermoplastic elastomer composition and a diene-basedrubber to form a laminate for use for a pneumatic tire.

Therefore, there is provided a laminate of an air permeation preventivelayer/an adhesive formed integrally in a cylindrical (tubular) shapewith the air permeation preventive layer of the thermoplastic elastomercomposition composed of a thermoplastic resin, as a continuous phase anda rubber composition, as a dispersed phase, at the inside and theadhesive composition at the outside has a superior in the bondabilitywith a tire carcass and contributing to the reduction of tire weight.

As the diene-based rubber, any diene-based rubber usable for a tire, forexample, natural rubber (NR), polyisoprene rubber (IR), various types ofstyrene-butadiene copolymer rubber (SBR), various types of polybutadienerubber (BR), acrylonitrile-butadiene copolymer rubber (NBR), and furtheran ethylene-propylene-diene copolymer (EPDM), (halogenated) butylrubber, etc. may be mentioned. These may be used alone or in any blendthereof.

As the resin components of the thermoplastic elastomer of the laminateaccording to the present invention, for example, polyamide-based resins(e.g., Nylon 6 (N6), Nylon 66 (N66), Nylon 11 (N11), Nylon 12 (N12),Nylon 610 (N610), Nylon 612 (N612), etc.), polyester-based resins (e.g.,polybutylene terephthalate (PBT), polyethylene terephthalate (PET),polyethylene isophthalate (PEI), etc.), polynitrile-based resins (e.g.,polyacrylonitrile (PAN), polymethacrylonitrile, etc.),polymethacrylate-based resins (e.g., polymethyl methacrylate (PMMA),polyethyl methacrylate, etc.), polyvinyl-based resins (e.g., vinylacetate, polyvinyl alcohol (PVA), polyvinylidene chloride (PDVC),polyvinyl chloride (PVC), etc.), cellulose-based resins (e.g., celluloseacetate, and cellulose acetate butyrate), fluorine-based resins (e.g.,polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), etc.),imide-based resins (e.g., an aromatic polyimide (PI)), etc. may bementioned.

The thermoplastic elastomer usable for the laminate according to thepresent invention is obtained by blending the thermoplastic resin and anelastomer. As the elastomer, for example, diene-based rubbers and thehydrogenates thereof (e.g., NR, IR, SBR, BR, NBR, etc.), olefin-basedrubbers (e.g., ethylenepropylene rubber (EPDM, EPM), IIR, etc.), acrylrubbers (e.g., ACM), halogenated rubbers (e.g., Br-IIR, Cl-IIR,brominated isobutylene paramethylstyrene copolymer (Br-IPMS), etc.),silicone rubbers (e.g., methylvinyl silicone rubber, dimethyl siliconerubber, etc.), sulfur-containing rubbers (e.g., polysulfide rubber),fluororubbers (e.g., a vinylidene fluoride-based rubber, afluorine-containing vinylether-based rubber), thermoplastic elastomers(e.g., a styrene-based elastomer, an olefin-based elastomer, anester-based elastomer, a urethane-based elastomer or a polyamide-basedelastomer), etc. may be mentioned. These may be used alone or in anyblend of any two or more types.

The elastomer components can be dynamically vulcanized when mixed withthe thermoplastic resin. Here, “dynamic vulcanization” means thethermoplastic resin, elastomer component and cross-linking agent are fedto, for example, a twin-screw mixer etc. and melt mixing the mixture,while the elastomer component is vulcanized. The vulcanization agent,vulcanization aid, vulcanization conditions (e.g., temperature andtime), etc. in the case of dynamic vulcanization should be suitablydetermined depending upon the composition of the elastomer componentadded and is not particularly limited. As the vulcanization agent, ageneral rubber vulcanization agent (or cross-linking agent) may be used.Specifically, as the sulfur-based vulcanization agent, sulfur powder,precipitated sulfur, etc. may be used in an amount of, for example, 0.5to 4 phr [parts by weight based upon 100 parts by weight of the rubbercomponent (polymer)].

Further, as an organic peroxide-based vulcanization agent, specifically,for example, dicumyl peroxide, di-t-butyl peroxide, t-butylcumylperoxide, benzoyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexine-3,2,5-dimethyl-2,5-di(t-butylperoxy)hexane,1,3-bis(t-butylperoxyisopropyl)benzene,4,4-di-t-butylperoxy-valerenate-n-butyl ester, etc. may be mentioned. Asa thiourea-based vulcanization accelerator, ethylenethiourea,diethylthiourea, etc. may be mentioned.

Further, the elastomer component may be used, together with generalrubber use compounding agents. For example, zinc white, stearic acid andoleic acid and the metal salts thereof, etc. may be used. The productionmethod of the thermoplastic elastomer composition comprises melt mixing,in advance, the thermoplastic resin component and elastomer component(in the case of rubber, unvulcanized) by a twin-screw kneader/extruderetc. to cause the elastomer component to disperse as a dispersed phase(i.e., domain) in the thermoplastic resin forming the continuous phase(i.e., matrix phase). When vulcanizing the elastomer component, it ispossible to add the vulcanization agent, while mixing so as to causedynamic vulcanization of the elastomer component. Further, the variouscompounding agents (other than the vulcanization agent) for thethermoplastic resin or elastomer component may be added during themixing, but it is preferable to mix them before the mixing. The kneaderused for mixing the thermoplastic resin and elastomer component is notparticularly limited. A screw extruder, kneader, Banbury mixer,twin-screw kneader/extruder, etc. may be used. As the melt kneadingconditions, the temperature should be at least the temperature at whichthe thermoplastic resin melts. Further, the shear rate at the time ofmixing is preferably 1000 to 7500 sec⁻¹. The overall mixing time ispreferably from 30 seconds to 10 minutes. When adding a vulcanizationagent, the vulcanization time after addition is preferably from 15seconds to 5 minutes. The thermoplastic elastomer composition preparedby the method is then extruded or calendered to form a sheet-like film.The film formation method may be based on the forming method of a usualthermoplastic resin or thermoplastic elastomer into a film.

The film thus obtained takes the structure of the thermoplastic resin(A) as a matrix in which the elastomer component (B) is dispersed as adispersed phase (i.e., domain). By adopting such a dispersed structure,thermoplastic processing becomes possible and the air permeationpreventive layer constituted by the film can be given sufficientflexibility and also sufficient rigidity due to the effect of thecontinuous phase constituted by the resin layer. Regardless of theamount of the elastomer component, at the time of shaping, a workabilityequal to that of a thermoplastic resin can be obtained. Therefore, ausual resin molding machine, that is, extrusion or calendering, may beused to form the film.

The ratio of the specific thermoplastic resin (A) and elastomercomponent (B), when blending the thermoplastic resin and elastomer, isnot particularly limited and should be suitably determined by thebalance of the film thickness, air permeation preventive property andflexibility, but the preferable range is, by weight ratio (A)/(B), 10/90to 90/10, more preferably 15/85 to 90/10.

The adhesive composition used in the present invention may contain, inaddition to the above essential components, various additives generallyused in conventional adhesive compositions such as zinc oxide, anantioxidant, a coloring agent. These additives may be used by generalmethods. The amounts of these additives may be made the conventionalgeneral amounts blended so long as the object of the present inventionis adversely affected.

EXAMPLES

Examples will now be used to further explain the present invention, butthe scope of the present invention is not limited to these Examples.

Examples 1 to 4 and Comparative Examples 1 to 6

An adhesive composition of each formulation shown in Table I was mixedby a single-screw extruder having a screw diameter of 40 mmφ and passedthrough an anti-sticking solution, then was cut by a cutter intopellets. On the other hand, a thermoplastic elastomer composition havingthe formulation shown in Table II was mixed by a twin-screw extruder,then cooled in water and cut by a cutter into pellets. These pelletswere extruded using 50 mmφ and 75 mmφ extruders and cylindrical stackingdies into cylindrical shapes having thicknesses of 50 μm and 150 μm. Thetest films thus obtained were subjected to the tests shown in Table I.

Test Methods for Evaluation

1) Tack Test

An adhesive composition of each formulation shown in Table I and thethermoplastic elastomer sheet shown in Table II were extruded using 50mmφ and 75 mmφ extruders and tubular stacking dies into cylindricalshapes having thicknesses of 50 μm and 150 μm. The result was cut to aband having a width of 1 cm and attached to the ring part of the tacktester, which was then pressed perpendicularly against a 10 cm squarepiece cut from the same sheet in the case of self tack and against theunvulcanized carcass member in the case of tack for the carcass layer.The force, when peeling off the same, was measured. The measurement wasconducted using a Toyoseiki PICMA tack tester under the followingconditions. The results are shown in Table I.

Measurement Conditions Dimensions of top sample: 12.7 mm × 152 mm Pressload: 4.90N Peeling speed: 120 mm/min Press time: 0 second Temperature:20° C. Relative humidity: 65%

2) Cylindrical Molding Workability Test

Each adhesive composition shown in Table I and the thermoplasticelastomer composition shown in Table II were extruded by the inflationmethod shown in FIG. 1 into a two-layer tubular shape having theadhesive layer at the outside. This was blown to a diameter of 355 mm,then folded by pinch rolls and taken-up (or wound-up) in that state. Thefollowing criteria were used for evaluation. The results are shown inTable I.

++: No problem in both extrudability and takeup

+: No problem in extrudability, while film tended somewhat to stick topinch rolls, but this did not become a major problem

±: No problem in extrudability, but film stuck to pinch rolls and takeupwas difficult

−: Extrusion did not go well

3) Tire Moldability Test

Each 355 mm thermoplastic elastomer/adhesive film laminate prepared bythe inflation machine shown in FIG. 1 was cut to a width of 360 mm, theninserted into a tire forming drum, wrapped around a carcass, beaded, andturned up. Next, the sides, belt, and cap were attached to thereby forma green tire. After formation, the degree of bonding of the tubular filmand carcass was visually observed by the following criteria. The resultsare shown in Table I.

++: Carcass rubber exactly followed and no raised parts or peeling seen

+: Some raised parts seen, but no peeling from carcass seen

±: Some peeling and rising from carcass requiring correction by handstitcher

−: Peeling from carcass over substantially entire circumference makingtransfer to vulcanization step impossible.

4) Bonding Test

Each thermoplastic elastomer film extruded and shaped together with anadhesive of Table I was laid over a 2 mm unvulcanized rubber sheet shownin Table III and vulcanized at 160° C. over 20 minutes. Each was cut toa strip having a width of 25 mm and a length of 100 mm. A cut was madeinto the center of the thermoplastic elastomer film in the widthdirection to thereby prepare a test sample. This was set in a UeshimaSeisakusho De-mattia crack tester and repeatedly subjected to continuoustensile strain by a chuck distance of 60 mm and a stroke of 10 mm500,000 times, then any peeling of the film from the cut part wasvisually observed and evaluated by the following criteria. The resultsare shown in Table I.

++: No peeling of film seen at all

+: Slight peeling seen from cut part, but due to destruction of rubberor adhesive material

−: Large peeling from cut part and forming interfacial peeling

TABLE I Formulation of Adhesive Composition Comp. Comp. Comp. Comp.Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 1 Ex. 2 Ex. 3 Ex. 4Formulation (parts by weight) E-GMA-VA (Bondfast 7B, SumitomoChemical)*¹ 60 — — — — — — — — — Epoxylated SBS (Epofriend A1020, Daicel— 50 10 50 50 50 50 80 50 50 Chemical Industries)*² SBS (Tufprene A,Asahi Kasei)*³ 40 50 90 50 50 50 50 20 50 50 Rosin ester (Pensel AD,Arakawa Chemical)*⁴ 70 70 — — — — — — — — Terpene resin (YS Resin D-105,Yasuhara — — 70 — 70 70 70 70 70 40 Chemical)*⁵ Aromatically modifiedterpene resin (YS Resin — — — 70 — — — — — 30 TR-105, YasuharaChemical)*⁶ Zinc oxide (Zinc White #3, Seido Chemical) 5 5 5 5 5 5 5 5 55 Stearic acid (Beads Stearic Acid, Kao) 1 1 1 1 — 1 1 1 1 1 Organicperoxide (Parkerdox 14, Kayaku Akzo) — — — — — 2.5 0.1 1 1 1 Testresults Self tack (N) 2.3 2.6 3.7 6.3 5.3 3.4 3.5 3.0 3.4 4.8cylindrical molding workability (+) (+) (+) (±) (±) (−)*¹ (++) (++) (++)(+) Tack with carcass (N) 3.8 4.0 7.7 4.6 8.0 7.4 5.9 7.4 10.1 Tiremoldability (−) (−) (+) (±) (++) (+) (+) (+) (++) Bonding test (+) (+)(−) (+) (+) (+) (++) (++) (+) *¹Molding was not possible. Footnotes ofTable I *¹Conventional adhesive (main ingredient: epoxy-modifiedethylene-vinyl acetate copolymer) *²Epoxy-modifiedstyrene-butadiene-styrene block copolymer *³Styrene-butadiene-styreneblock copolymer *⁴tackifing resin *⁵tackifing resin *⁶tackifing resin

TABLE II Formulation of Thermoplastic Elastomer Formulation amount Nameof (parts by material Name of product Manufacturer weight) Br-IPMSEXXPRO 89-4 Exxon Mobil 100 Chemical PA 6/66 Ube Nylon 5033B UbeIndustries 30 PA 11 Rilsan BESN O TL Atofina Japan 40 Zinc oxide ZincWhite #3 Seido Chemical 0.2 Stearic acid Beads Stearic Acid Kao 0.5 ZincZinc stearate Seido Chemical 0.3 stearate Plasticizer BM-4 DaihachiChemical 10 Industry Antioxidant Irganox 1098 Ciba Specialty 0.5Chemicals

TABLE III Rubber Formulation Formulation amount (parts by Name ofmaterial Name of product Manufacturer weight) NR RSS#3 — 60 SBR Nipol1502 Nippon Zeon 40 Carbon Seast 300 Tokai Carbon 60 Zinc oxide ZincWhite #3 Seido Chemical 5 Stearic acid Beads Stearic Acid Kao 1Antioxidant Nocrac RD Ouchi Shinko 1 Chemical Industrial Aromatic oilExtract #4S Showa Shell Oil 10 Sulfur Oil-extended sulfur Karuizawa 3Refinery Vulcanization Noccelar CZ Ouchi Shinko 1 accelerator ChemicalIndustrial

In Table I, Comparative Example 1 is an example of the case usingE-GMA-VA for the polymer of the adhesive and rosin ester for thetackifier and suffered from insufficient tack with the carcass andinability of tire molding. Comparative Example 2 is an example of thecase using an SBS system for the polymer of the adhesive and a rosinester system for the tackifier and suffered from insufficient tack withthe carcass and inability of molding. Comparative Example 3 is anexample of the case where the amount of the epoxy-modifiedstyrene-butadiene-styrene block copolymer (ESBS) is less than theprescribed amount and suffered from poor results in the peeling test.Comparative Example 4 is an example of the case using only anaromatically modified terpene resin for the tackifier and suffered fromtoo much self tack and moldability is difficult. Comparative Example 5is an example of the case where no stearic acid (i.e., internal releaseagent) is used and suffers from too much self tack and moldability isdifficult. Comparative Example 6 is an example of the case where thecross-linking agent, i.e., the organic peroxide is excessively containedand suffered from the production of a large amount of gel particles dueto scorching of the adhesive during the extrusion.

Contrary to the above, Examples 1 and 3 are examples of the organicperoxide, i.e., the cross-linking agent, contained in the prescribedamounts and are free from scorching of the adhesive during extrusionwork, superior in balance of self tack and tack with the carcass, andexcellent in peeling test results as well. Example 2 is an example wherethe formulation amount of the epoxy-modified SBS is increase and isimproved in bondability. Example 4 is an example of a case making thetackifier a blend of a terpene resin and aromatically modified terpeneresin and is improved much more in tack with the carcass.

INDUSTRIAL APPLICABILITY

The air permeation preventive layer/an adhesive layer laminate of thepresent invention is superior in the workability in tire production,superior in bondability with a tire carcass, can contribute to thedecrease in tire weight, and is suitable for use as a pneumatic tire.

1. A laminate of an air permeation preventive layer/an adhesive layerprovided with (I) an air permeation preventive layer comprising athermoplastic elastomer composition containing a thermoplastic resin, asa continuous phase, and a rubber composition dispersed therein, as adispersed phase, and (II) arranged on one surface of the air permeationpreventive layer, an adhesive composition layer having a thickness of100 μm or less formed from an adhesive composition having a self-tack ofless than 5N and a tack to an unvulcanized diene-based rubber of10.1-20N containing (i) a total of 100 parts by weight of athermoplastic elastomer containing 50 parts by weight or more of anepoxy-modified styrene-butadiene-based block copolymer so that anoxirane oxygen content becomes 1 to 3% by weight, (ii) a total of 30 to200 parts by weight of a terpene resin (A) having a weight averagemolecular weight Mw of 1000 or less and a softening point of 60 to 120°C. and an aromatically modified terpene resin (B) having a weightaverage molecular weight Mw of 1000 or less and a softening point of 60to 120° C., in a ratio by weight of (A):(B)=70:30 to 50:50, (iii) 0.1 to3 parts by weight of an internal mold release agent and (iv) 0.1 to 2parts by weight of an organic peroxide having a one-minute half-lifetemperature of 160° C. or more.
 2. A laminate of an air permeationpreventive layer/an adhesive layer as claimed in claim 1, comprising theair permeation preventive layer of the thermoplastic elastomercomposition comprising a thermoplastic resin as a continuous phase and arubber composition as a dispersed phase at the inside and the adhesivecomposition at the outside, which are integrally formed in a cylindricalshape.
 3. A laminate as claimed in claim 1, wherein said thermoplasticresin is a polyamide.
 4. A laminate as claimed in claim 1 wherein therubber composition is a rubber composed of a partially halogenatedcopolymer of isobutylene and paramethylstyrene.
 5. A laminate as claimedin claim 1, wherein the terpene resin is a dipentene resin.
 6. Alaminate as claimed in claim 1, wherein the organic peroxide is dicumylperoxide, 2,5-dimethyl-2, 5-di(t-butylperoxy) hexane or2,5-dimethyl-2,5-di(t-butylperoxy) hexine-3.
 7. A pneumatic tire using alaminate according to claim
 1. 8. A laminate as claimed in claim 2,wherein said thermoplastic resin is a polyamide.
 9. A laminate asclaimed in claim 8 wherein the rubber composition is a rubber composedof a partially halogenated copolymer of isobutylene andparamethylstyrene.
 10. A laminate as claimed in claim 2 wherein therubber composition is a rubber composed of a partially halogenatedcopolymer of isobutylene and paramethylstyrene.
 11. A laminate asclaimed in claim 3 wherein the rubber composition is a rubber composedof a partially halogenated copolymer of isobutylene andparamethylstyrene.
 12. A laminate as claimed in claim 2, wherein theterpene resin is a dipentene resin.
 13. A laminate as claimed in claim3, wherein the terpene resin is a dipentene resin.
 14. A laminate asclaimed in claim 2, wherein the organic peroxide is dicumyl peroxide,2,5-dimethyl-2, 5-di(t-butylperoxy) hexane or2,5-dimethyl-2,5-di(t-butylperoxy) hexine-3.
 15. A laminate as claimedin claim 3, wherein the organic peroxide is dicumyl peroxide,2,5-dimethyl-2, 5-di(t-butylperoxy) hexane or2,5-dimethyl-2,5-di(t-butylperoxy) hexine-3.
 16. A laminate as claimedin claim 4, wherein the organic peroxide is dicumyl peroxide,2,5-dimethyl-2, 5-di(t-butylperoxy) hexane or2,5-dimethyl-2,5-di(t-butylperoxy) hexine-3.
 17. A laminate as claimedin claim 5, wherein the organic peroxide is dicumyl peroxide,2,5-dimethyl-2, 5-di(t-butylperoxy) hexane or2,5-dimethyl-2,5-di(t-butylperoxy) hexine-3.
 18. A laminate as claimedin claim 6, wherein the organic peroxide is dicumyl peroxide,2,5-dimethyl-2, 5-di(t-butylperoxy) hexane or2,5-dimethyl-2,5-di(t-butylperoxy) hexine-3.
 19. A pneumatic tire usinga laminate according to claim
 2. 20. A laminate as claimed in claim 5,wherein the aromatically modified terpene resin is the terpene resin isa dipentene resin copolymerized with an aromatic vinyl monomer.